In a typical inkjet printer, a print head deposits ink onto a surface of a print medium to form print images, e.g., including text. A page-wide print head can print the width of a page without moving, while a moving print head can be moved along the width of the page. In either case, the print head is designed to print a band or “swath” at a time. A media-advance mechanism advances the media longitudinally past the print head so that the image can extend longitudinally along the medium. (Herein, “length” and “width” refer to dimensions respectively along and transverse to the direction of media travel during printing, regardless of the media dimensions.)
As the print medium passes the print head, it is typically supported on the side opposite the print head by platen, so that the medium is a known distance from the print head. An inkjet platen may support the medium on a series of ribs. Gaps between the ribs can accommodate a possible deformation of the print media as wet ink is deposited. Without the gaps between the ribs, any deformation of the media would be toward the print head, which would have a more deleterious impact on print quality.